Depending on which version of the Universal Carbine you have there could be a way to use the Choate stock. The early models used mostly USGI parts except for the trigger housing group. This is why Choate says it only fits the military model carbines. The trigger housing on the Universal is wider than the GI. If you have one of these, then you can replace it with a USGI one. It may require a little fitting to get the right fit though. Depending of which of the later models you may have, it may be possible. There were several modifications that Universal did to the gas piston, slide and receiver that may not allow the Choate stock to fit. Some models use a solid pin, others use a roll pin to hold the trigger housing to the receiver. I've used a nail cut to length on ones with roll pins. The internal parts can change over. SARCO has stripped trigger housings that are not too expensive. I'm sure you could find videos on Youtube that show how its done. You may be able to find someone in your area that is familar with carbines to help you. It's not all that difficult. Also, I think that you could just open up the area of the Choate stock where the trigger housing fits with a file and sanding for the barrel and receiver to fit. I replaced the trigger housing on my Universal and it fits the military stock just fine. I use my Universal to hunt with and it will hold a 1" to 1 1/2 group at 100 yds. It wears a scope as my old eyes don't see as well as they used to. My Inland with open sights being shot by some with younger eyes does pretty good as well. Hope this helps some.
Dave...